WO2013128723A1 - 距離センサ及び距離画像センサ - Google Patents
距離センサ及び距離画像センサ Download PDFInfo
- Publication number
- WO2013128723A1 WO2013128723A1 PCT/JP2012/079415 JP2012079415W WO2013128723A1 WO 2013128723 A1 WO2013128723 A1 WO 2013128723A1 JP 2012079415 W JP2012079415 W JP 2012079415W WO 2013128723 A1 WO2013128723 A1 WO 2013128723A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- region
- charge
- signal
- pixel
- semiconductor
- Prior art date
Links
- 239000004065 semiconductor Substances 0.000 claims abstract description 166
- 238000012546 transfer Methods 0.000 claims description 48
- 239000000758 substrate Substances 0.000 claims description 39
- 230000010363 phase shift Effects 0.000 claims description 6
- 230000004044 response Effects 0.000 abstract description 6
- 238000001514 detection method Methods 0.000 description 44
- 238000010586 diagram Methods 0.000 description 25
- 230000004048 modification Effects 0.000 description 25
- 238000012986 modification Methods 0.000 description 25
- 239000012535 impurity Substances 0.000 description 9
- 238000004364 calculation method Methods 0.000 description 8
- 238000009825 accumulation Methods 0.000 description 6
- 238000009826 distribution Methods 0.000 description 6
- 238000003384 imaging method Methods 0.000 description 6
- 230000006872 improvement Effects 0.000 description 6
- 238000009792 diffusion process Methods 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 230000006870 function Effects 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 3
- 229920005591 polysilicon Polymers 0.000 description 3
- 238000005036 potential barrier Methods 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000001360 synchronised effect Effects 0.000 description 2
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
- H01L27/14601—Structural or functional details thereof
- H01L27/14603—Special geometry or disposition of pixel-elements, address-lines or gate-electrodes
- H01L27/14607—Geometry of the photosensitive area
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
- G01S17/06—Systems determining position data of a target
- G01S17/08—Systems determining position data of a target for measuring distance only
- G01S17/10—Systems determining position data of a target for measuring distance only using transmission of interrupted, pulse-modulated waves
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/88—Lidar systems specially adapted for specific applications
- G01S17/89—Lidar systems specially adapted for specific applications for mapping or imaging
- G01S17/894—3D imaging with simultaneous measurement of time-of-flight at a 2D array of receiver pixels, e.g. time-of-flight cameras or flash lidar
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/483—Details of pulse systems
- G01S7/486—Receivers
- G01S7/4861—Circuits for detection, sampling, integration or read-out
- G01S7/4863—Detector arrays, e.g. charge-transfer gates
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
- H01L27/14601—Structural or functional details thereof
- H01L27/14609—Pixel-elements with integrated switching, control, storage or amplification elements
- H01L27/1461—Pixel-elements with integrated switching, control, storage or amplification elements characterised by the photosensitive area
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
- H01L27/14601—Structural or functional details thereof
- H01L27/14609—Pixel-elements with integrated switching, control, storage or amplification elements
- H01L27/14612—Pixel-elements with integrated switching, control, storage or amplification elements involving a transistor
Definitions
- the present invention relates to a distance sensor and a distance image sensor.
- a TOF (Time-Of-Flight) type distance image sensor (distance sensor) is known (for example, see Non-Patent Document 1).
- the distance image sensor described in this document includes a charge generation region in which charge is generated in response to incident light, a charge collection region disposed inside the charge generation region so as to be surrounded by the charge generation region, and a charge generation region A charge discharge region disposed outside the charge generation region so as to surround the charge generation region, an inner gate electrode disposed on the charge generation region and allowing the charge generation region to flow into the charge collection region according to an input signal, and a charge And an outer discharge gate electrode which is disposed on the generation region and allows the charge in the charge generation region to flow into the charge discharge region in accordance with an input signal.
- the charge collection region is disposed at the center of the polygonal pixel region, and the charge discharge region is disposed over the entire circumference of the pixel region. Due to the potential difference applied to the inner gate electrode and the outer discharge gate electrode, a potential gradient is formed in a region immediately below the inner gate electrode and the outer discharge gate electrode. According to this potential gradient, the charge generated in the charge generation region moves to the charge collection region or the charge discharge region.
- the distance image sensor described in the above document has the following problems.
- the aperture ratio which is the ratio of the area of the charge generation region to the area of the pixel region is small.
- the charge generation area extends to the end of the pixel area, the charge discharge area cannot be arranged although the aperture ratio is large. Since the charge transfer time is proportional to the movement distance, the charge generated in the area near the corner of the pixel area in the charge generation area has a long movement distance to the charge collection area and a long transfer time. As a result, the transfer efficiency of charges to the charge collection region is poor.
- An object of the present invention is to provide a distance sensor and a distance image sensor capable of improving the aperture ratio and the charge transfer efficiency.
- the present invention is a distance sensor, and a charge generation region in which an outer edge extends to each side of a pixel region excluding corners of a polygonal pixel region, and charges are generated according to incident light.
- a signal charge collection region that collects signal charge from the charge generation region and is disposed at the center of the pixel region and surrounded by the charge generation region;
- An unnecessary charge collection region that is disposed outside the region and collects unnecessary charges from the charge generation region, a photogate electrode disposed on the charge generation region, and a signal charge collection region and the charge generation region And arranged between the transfer electrode that causes the signal charge from the charge generation region to flow into the signal charge collection region according to the input signal and the unnecessary charge collection region and the charge generation region, and according to the input signal.
- Charge generation area And a, and the unnecessary charge collection gate electrode to flow into the unnecessary charge collecting region unnecessary charges from.
- the outer edge of the charge generation region extends to each side of the pixel region excluding the corners of the polygonal pixel region, the area of the charge generation region is expanded. Thereby, an aperture ratio can be improved.
- the charge generation region extends to the corner of the pixel region, the charge generated in the region corresponding to the corner of the pixel region in the charge generation region is collected in the signal charge collected at the center of the pixel region.
- the moving distance to the area is long. For this reason, the transfer time of the charge generated in the region corresponding to the corner to the signal charge collection region becomes long, and the transfer efficiency of the signal charge to the charge collection region is deteriorated.
- the present invention since the charge generation region is not disposed at the corner of the pixel region, the signal charge is not transferred from the region where the movement distance becomes long. For this reason, the transfer efficiency of the signal charge to the charge collection region is improved.
- an unnecessary charge collection region is disposed at the corner of the pixel region where no charge generation region is disposed. Therefore, the unnecessary charge collection region can be disposed without hindering improvement in the aperture ratio and the charge transfer efficiency.
- a plurality of adjacent pixel regions may be provided, the charge generation regions of the plurality of pixel regions may be integrally formed, and the photogate electrodes of the plurality of pixel regions may be integrally formed. Further, the unnecessary charge collection regions of the plurality of pixel regions may be integrally formed. In either case, the sensor area utilization efficiency can be increased. As a result, the spatial resolution can be improved.
- the charge transfer signals having different phases may be applied to the transfer electrodes of the plurality of pixel regions, respectively. In this case, distance calculation is performed based on outputs from a plurality of adjacent pixel regions.
- the transfer electrode may be supplied with a charge transfer signal to which a phase shift is intermittently given at a predetermined timing.
- the distance is calculated based on the output from one pixel area. For this reason, variation in distance calculation can be reduced as compared with a configuration in which distance is calculated based on outputs from a plurality of pixel regions.
- the utilization efficiency of the sensor area can be increased, and the spatial resolution can be improved.
- the region where the readout circuit that reads out a signal corresponding to the amount of charge accumulated in the signal charge collection region may be located outside the pixel region along one side of the pixel region.
- a region in which a readout circuit that reads a signal corresponding to the amount of charge accumulated in the signal charge collection region may be located at one corner of the pixel region.
- the reading circuit can be arranged without hindering improvement in the aperture ratio and the charge transfer efficiency.
- the signal charge collection region may be rectangular in plan view, and the transfer electrode may have a substantially polygonal ring shape.
- the present invention provides an imaging region including a plurality of units arranged one-dimensionally or two-dimensionally on a semiconductor substrate, and obtains a distance image based on the amount of charge output from the unit.
- Each of the image sensors is a distance sensor.
- the aperture ratio and the charge transfer efficiency can be improved.
- the present invention it is possible to provide a distance sensor and a distance image sensor capable of improving the aperture ratio and the charge transfer efficiency.
- FIG. 1 is an explanatory diagram showing a configuration of a distance measuring device according to an embodiment of the present invention.
- FIG. 2 is a diagram for explaining a cross-sectional configuration of the distance image sensor.
- FIG. 3 is a schematic plan view of the distance image sensor.
- FIG. 4 is a schematic diagram for explaining the configuration of the pixel region of the distance image sensor.
- FIG. 5 is a diagram showing a cross-sectional configuration along the line VV in FIG.
- FIG. 6 is a diagram showing a potential distribution for explaining the charge accumulation operation.
- FIG. 7 is a diagram showing a potential distribution for explaining the charge accumulation operation.
- FIG. 8 is a diagram showing a potential distribution for explaining the charge discharging operation.
- FIG. 9 is a schematic diagram for explaining a configuration of a pixel.
- FIG. 1 is an explanatory diagram showing a configuration of a pixel.
- FIG. 2 is a diagram for explaining a cross-sectional configuration of the distance image sensor.
- FIG. 10 is a timing chart of various signals.
- FIG. 11 is a schematic diagram for explaining a configuration of a pixel of a distance image sensor according to a modification.
- FIG. 12 is a timing chart of various signals.
- FIG. 13 is a schematic diagram for explaining a configuration of a pixel of a distance image sensor according to a modification.
- FIG. 14 is a timing chart of various signals.
- FIG. 15 is a schematic diagram for explaining a configuration of a pixel of a distance image sensor according to a modification.
- FIG. 16 is a schematic diagram for explaining a configuration of pixels of a distance image sensor according to a modification.
- FIG. 17 is a schematic diagram for explaining a configuration of a pixel of a distance image sensor according to a modification.
- FIG. 1 is an explanatory diagram showing the configuration of the distance measuring apparatus.
- the distance measuring device includes a distance image sensor 1, a light source 3 that emits near-infrared light, a drive circuit 4, a control circuit 2, and an arithmetic circuit 5.
- Drive circuit 4 supplies a pulse drive signal S P to the light source 3.
- the control circuit 2 includes first and second gate electrode included in each pixel of the range image sensor 1 (TX1, TX2: see FIG. 4), the pulsed driving signal S gate signal detection is synchronous with the P S 1, S 2 give.
- the arithmetic circuit 5 uses a signal d ′ (m, n) indicating distance information read from the first to second semiconductor regions (FD1 to FD2: see FIG. 4) of the distance image sensor 1 as a target such as a pedestrian.
- the distance to the object H is calculated.
- the distance in the horizontal direction D from the distance image sensor 1 to the object H is defined as d.
- the control circuit 2 also outputs a charge transfer signal S 3 to be described later.
- the control circuit 2 is input to the pulse drive signal S P to the switch 4b of the driving circuit 4.
- a light projecting light source 3 comprising an LED or a laser diode is connected to a power source 4a via a switch 4b.
- a drive current having the same waveform as the pulse drive signal S P is supplied to the light source 3, the pulse light L P as a probe light for distance measurement from the light source 3 is outputted Is done.
- the pulse light L P is irradiated on the object H, the pulse light is reflected by the object H.
- the reflected pulsed light, as the pulse light L D the distance is incident on the image sensor 1, the pulse detection signal S D is outputted.
- the distance image sensor 1 is disposed on the wiring board 10.
- a signal d ′ (m, n) having distance information is output from each pixel of the distance image sensor 1 via the wiring on the wiring substrate 10.
- the waveform of the pulse drive signal S P is a square wave of period T.
- V (t) 1 (provided that 0 ⁇ t ⁇ (T / 2))
- V (t) 0 (provided that (T / 2) ⁇ t ⁇ T)
- V (t + T) V (t)
- the waveforms of the detection gate signals S 1 and S 2 are square waves having a period T.
- the voltage V (t) is given by the following equation.
- V (t) 0 (provided that (T / 2) ⁇ t ⁇ T)
- V (t + T) V (t)
- V (t) 0 (provided that 0 ⁇ t ⁇ (T / 2))
- V (t) 1 (provided that (T / 2) ⁇ t ⁇ T)
- V (t + T) V (t)
- the pulse signal S P, S 1, S 2 , S D has all pulse period 2 ⁇ T P.
- the amount of charge generated in the distance image sensor 1 when the detection gate signal S 1 and the pulse detection signal SD are both “1” is defined as Q1.
- Detection gate signal S 2 and the pulse detection signal S D are both a Q2 the amount of charge generated by the distance image sensor within 1 when "1".
- Phase difference detection gate signals S 1 and the pulse detection signal S D is the overlap period when the detection gate signal S 2 and the pulse detection signal S D is "1", the charge amount Q2 generated in the range image sensor 1 Is proportional to That is, the charge amount Q2 is the charge amount for the period logical product of the detection gate signal S 2 and the pulse detection signal S D is "1".
- the arithmetic circuit 5 can calculate the distance d.
- the above-described pulse is repeatedly emitted, and the integrated value can be output as the respective charge amounts Q1 and Q2.
- the ratio of the charge amounts Q1 and Q2 to the total charge amount corresponds to the above-described phase difference, that is, the distance to the object H.
- the arithmetic circuit 5 calculates the distance to the object H according to this phase difference.
- a coefficient ⁇ for correcting the latter is obtained in advance, and the product after shipping is obtained by multiplying the calculated distance d by the coefficient ⁇ .
- the calculation distance d may be used.
- the distance calculation can be performed after performing the calculation for correcting the light speed c.
- the relationship between the signal input to the arithmetic circuit and the actual distance may be stored in advance in the memory, and the distance may be calculated by a lookup table method.
- the calculation method can also be changed depending on the sensor structure, and a conventionally known calculation method can be used for this.
- FIG. 2 is a diagram for explaining a cross-sectional configuration of the distance image sensor.
- the distance image sensor 1 is a surface incident type distance image sensor and includes a semiconductor substrate 1A.
- the range image sensor 1 a pulse light L D from the light incident surface 1FT of the semiconductor substrate 1A is incident.
- the back surface 1BK opposite to the light incident surface 1FT of the distance image sensor 1 is connected to the wiring substrate 10 via the adhesion region AD.
- the adhesion region AD has an insulating adhesive or filler.
- the distance image sensor 1 includes a light shielding layer LI having an opening formed at a predetermined position.
- the light shielding layer LI is disposed in front of the light incident surface 1FT.
- FIG. 3 is a schematic plan view of the distance image sensor.
- the semiconductor substrate 1 ⁇ / b> A has an imaging region 1 ⁇ / b> B composed of a plurality of pixels P (m, n) arranged two-dimensionally. From each pixel P (m, n), two charge amounts (Q1, Q2) are output as the signal d '(m, n) having the above-mentioned distance information. Each pixel P (m, n) outputs a signal d '(m, n) corresponding to the distance to the object H as a minute distance measuring sensor. Therefore, if the reflected light from the object H is imaged on the imaging region 1B, a distance image of the object as a collection of distance information to each point on the object H can be obtained.
- One pixel P (m, n) functions as one distance sensor.
- FIG. 4 is a schematic diagram for explaining the configuration of the pixels of the distance image sensor.
- FIG. 5 is a diagram showing a cross-sectional configuration along the line VV in FIG.
- the distance image sensor 1 includes a semiconductor substrate 1A having a light incident surface 1FT and a back surface 1BK facing each other.
- the semiconductor substrate 1A has a p-type first substrate region 1Aa located on the back surface 1BK side, and a p ⁇ -type second substrate region 1Ab located on the light incident surface 1FT side.
- the second substrate region 1Ab has a lower impurity concentration than the first substrate region 1Aa.
- the semiconductor substrate 1A can be obtained, for example, by growing a p ⁇ type epitaxial layer having an impurity concentration lower than that of the semiconductor substrate on the p type semiconductor substrate.
- Each pixel P (m, n) of the distance image sensor 1 includes two pixel regions PA1 and PA2 adjacent in the row direction or the column direction. That is, in the distance image sensor 1, the first unit arranged in the pixel area PA1 and the second unit arranged in the pixel area PA2 are arranged adjacent to each other in the row direction and the column direction. The first and second units arranged adjacent to each other in the row direction or the column direction form one pixel P (m, n).
- the pixel areas PA1 and PA2 have a substantially polygonal shape in plan view. In the present embodiment, the first and second semiconductor regions FD1, FD2 have a rectangular shape (specifically, a square shape).
- the pixel area PA1 and the pixel area PA2 are alternately arranged in the row direction and the column direction in the imaging area 1B, and are continuous in the row direction and the column direction.
- the distance image sensor 1 includes a photogate electrode PG1, a first gate electrode TX1, a plurality of third gate electrodes TX3, a first semiconductor region FD1, and a plurality of third semiconductor regions FD3 in the pixel region PA1. I have.
- the distance image sensor 1 includes a photogate electrode PG2, a second gate electrode TX2, a plurality of third gate electrodes TX3, a second semiconductor region FD2, and a plurality of third semiconductor regions FD3 in the pixel region PA2. I have.
- the photogate electrodes PG1 and PG2 are provided on the light incident surface 1FT via the insulating layer 1E, and are continuously arranged in the row direction and the column direction.
- the first to third gate electrodes TX1, TX2, TX3 are provided on the light incident surface 1FT via the insulating layer 1E, and are adjacent to the photogate electrodes PG1, PG2.
- Each of the first to third semiconductor regions FD1, FD2, and FD3 accumulates charge that flows into a region immediately below the corresponding gate electrode TX1, TX2, and TX3.
- the semiconductor substrate 1A of the present embodiment is made of Si
- the insulating layer 1E is made of SiO 2.
- openings LIa are formed in regions corresponding to the pixel regions PA1 and PA2, respectively.
- the opening LIa is formed in the light shielding layer LI continuously in the row direction and the column direction.
- Light reflected light from the object H enters the semiconductor substrate 1A through the opening LIa of the light shielding layer LI. Therefore, the light receiving region is defined in the semiconductor substrate 1A by the opening LIa.
- the light shielding layer LI is made of a metal such as aluminum, for example.
- the photogate electrode PG1 is disposed corresponding to the opening LIa in the pixel region PA1.
- the photogate electrode PG2 is disposed corresponding to the opening LIa in the pixel region PA2.
- the photogate electrodes PG1 and PG2 also correspond to the shape of the opening LIa.
- the outer edges of the photogate electrodes PG1 and PG2 extend to the sides of the pixel regions PA1 and PA2 except for the corners of the pixel regions PA1 and PA2.
- the photogate electrodes PG1 and PG2 are continuous in the row direction and the column direction because their outer edges extend to the sides of the pixel regions PA1 and PA2.
- the photogate electrodes PG1 and PG2 have an outer contour shape of a substantially “+” shape and an inner contour shape of a substantially rectangular shape (specifically, a square shape).
- the photogate electrodes PG1 and PG2 are made of polysilicon, but other materials may be used.
- the first semiconductor region FD1 is disposed inside the photogate electrode PG1 so as to be surrounded by the photogate electrode PG1.
- the first semiconductor region FD1 is spatially spaced from the region immediately below the photogate electrode PG1. That is, the first semiconductor region FD1 is arranged inside the light receiving region and spatially separated from the light receiving region so as to be surrounded by the light receiving region.
- the second semiconductor region FD2 is disposed inside the photogate electrode PG2 so as to be surrounded by the photogate electrode PG2.
- the second semiconductor region FD2 is spatially spaced from the region immediately below the photogate electrode PG2. That is, the second semiconductor region FD2 is disposed inside the light receiving region and spatially separated from the light receiving region so as to be surrounded by the light receiving region.
- the first and second semiconductor regions FD1, FD2 have a substantially polygonal shape in plan view.
- the first and second semiconductor regions FD1, FD2 have a rectangular shape (specifically, a square shape).
- the first and second semiconductor regions FD1, FD2 function as signal charge collection regions.
- the first and second semiconductor regions FD1, FD2 are regions made of an n-type semiconductor with a high impurity concentration, and are floating diffusion regions.
- the first gate electrode TX1 is disposed between the photogate electrode PG1 (light receiving region) and the first semiconductor region FD1.
- the first gate electrode TX1 is located outside the first semiconductor region FD1 so as to surround the first semiconductor region FD1, and is located inside the photogate electrode PG1 so as to be surrounded by the photogate electrode PG1. .
- the first gate electrode TX1 is arranged spatially separated from the photogate electrode PG1 and the first semiconductor region FD1 so as to be sandwiched between the photogate electrode PG1 and the first semiconductor region FD1.
- the second gate electrode TX2 is disposed between the photogate electrode PG2 (light receiving region) and the second semiconductor region FD2.
- the second gate electrode TX2 is located outside the second semiconductor region FD2 so as to surround the second semiconductor region FD2, and is located inside the photogate electrode PG2 so as to be surrounded by the photogate electrode PG2. .
- the second gate electrode TX2 is arranged spatially separated from the photogate electrode PG2 and the second semiconductor region FD2 so as to be sandwiched between the photogate electrode PG2 and the second semiconductor region FD2.
- the first and second gate electrodes TX1 and TX2 have a substantially polygonal ring shape in plan view.
- the first and second gate electrodes TX1, TX2 have a rectangular ring shape.
- the first and second gate electrodes TX1, TX2 are made of polysilicon, but other materials may be used.
- the first and second gate electrodes TX1, TX2 function as transfer electrodes.
- Each third semiconductor region FD3 is disposed at the corners of the pixel regions PA1 and PA2 and outside the photogate electrodes PG1 and PG2.
- the third semiconductor region FD3 is spatially spaced from the region immediately below the photogate electrodes PG1, PG2. That is, the third semiconductor region FD3 is disposed outside the light receiving region and spatially separated from the light receiving region.
- the third semiconductor region FD3 has a substantially polygonal shape in plan view in each of the pixel regions PA1 and PA2.
- the third semiconductor region FD3 has a substantially rectangular shape (specifically, a square shape).
- the third semiconductor regions FD3 adjacent in the row direction and the column direction are integrally formed.
- the four third semiconductor regions FD3 located at the center of the pixel regions PA1 and PA2 have one rectangular shape (in detail, , One square shape).
- the third semiconductor region FD3 functions as an unnecessary charge collection region.
- the third semiconductor region FD3 is a region made of an n-type semiconductor with a high impurity concentration, and is a floating diffusion region.
- the third gate electrode TX3 is disposed between the photogate electrodes PG1, PG2 (light receiving regions) and the third semiconductor region FD3.
- the third gate electrode TX3 is spatially spaced from the photogate electrodes PG1, PG2 and the third semiconductor region FD3 so as to be sandwiched between the photogate electrodes PG1, PG2 and the third semiconductor region FD3.
- the third gate electrode TX3 is made of polysilicon, but other materials may be used.
- the third gate electrode TX3 functions as an unnecessary charge collection gate electrode.
- the third gate electrode TX3 has an “L” shape in plan view in each of the pixel regions PA1 and PA2.
- the third gate electrode TX3 is continuous with the third gate electrode TX3 adjacent in the row direction and the column direction by extending the respective end portions to the sides of the pixel regions PA1 and PA2. That is, in the four pixel regions PA1 and PA2 adjacent in the row direction and the column direction, the four third gate electrodes TX3 located at the center of these pixel regions PA1 and PA2 have a substantially rectangular ring shape.
- the four third gate electrodes TX3 having a substantially rectangular ring shape as a whole are positioned outside the four third semiconductor regions FD3 so as to surround the four third semiconductor regions FD3 having a rectangular shape as a whole. .
- the photogate electrode PG1 and the first gate electrode TX1 are arranged concentrically in the order of the first gate electrode TX1 and the photogate electrode PG1 from the first semiconductor region FD1 side with the first semiconductor region FD1 as the center.
- the photogate electrode PG2 and the second gate electrode TX2 are arranged concentrically in the order of the second gate electrode TX2 and the photogate electrode PG2 from the second semiconductor region FD2 side with the second semiconductor region FD2 as the center.
- the thickness / impurity concentration of each region is as follows.
- First substrate region 1Aa of semiconductor substrate 1A thickness 5 to 700 ⁇ m / impurity concentration 1 ⁇ 10 18 to 10 20 cm ⁇ 3
- Second substrate region 1Ab of semiconductor substrate 1A thickness 3 to 50 ⁇ m / impurity concentration 1 ⁇ 10 13 to 10 16 cm ⁇ 3
- First and second semiconductor regions FD1, FD2 thickness 0.1 to 0.4 ⁇ m / impurity concentration 1 ⁇ 10 18 to 10 20 cm ⁇ 3
- Third semiconductor region FD3 thickness 0.1 to 0.4 ⁇ m / impurity concentration 1 ⁇ 10 18 to 10 20 cm ⁇ 3
- the insulating layer 1E is provided with contact holes (not shown) for exposing the surfaces of the first to third semiconductor regions FD1, FD2, and FD3.
- a conductor (not shown) for connecting the first to third semiconductor regions FD1, FD2, and FD3 to the outside is disposed in the contact hole.
- the light shielding layer LI covers a region where the first to third gate electrodes TX1, TX2, TX3 and the first to third semiconductor regions FD1, FD2, FD3 are arranged in the semiconductor substrate 1A, and light enters the region. Is prevented. Thereby, generation
- the region corresponding to the photogate electrodes PG1 and PG2 in the semiconductor substrate 1A functions as a charge generation region in which charges are generated according to incident light. Therefore, the charge generation region corresponds to the shape of the photogate electrodes PG1 and PG2 and the opening LIa. That is, the outer edge of the charge generation region extends to each side of the pixel regions PA1 and PA2 except for the corners of the pixel regions PA1 and PA2 in the pixel regions PA1 and PA2. Specifically, in each of the pixel regions PA1 and PA2, in the charge generation region, the outer contour shape has a substantially “+” shape, and the inner contour shape has a substantially rectangular shape (specifically, a square shape). .
- the charge generation region is continuous in the row direction and the column direction by extending each outer edge to each side of the pixel regions PA1 and PA2.
- the potential below the first gate electrode TX1 is lower than the potential of the region immediately below the photogate electrodes PG1 and PG2 in the semiconductor substrate 1A. Become. Thus, negative charges (electrons) are drawn in the direction of the first gate electrode TX1 and accumulated in the potential well formed by the first semiconductor region FD1.
- the first gate electrode TX1 allows signal charges to flow into the first semiconductor region FD1 in accordance with the input signal.
- An n-type semiconductor includes a positively ionized donor, has a positive potential, and attracts electrons.
- a low level signal for example, ground potential
- a potential barrier is generated by the first gate electrode TX1. Accordingly, the charge generated in the semiconductor substrate 1A is not drawn into the first semiconductor region FD1.
- the potential below the second gate electrode TX2 is lower than the potential of the region immediately below the photogate electrodes PG1 and PG2 in the semiconductor substrate 1A. Become. Thereby, negative charges (electrons) are drawn in the direction of the second gate electrode TX2 and accumulated in the potential well formed by the second semiconductor region FD2.
- the second gate electrode TX2 allows signal charges to flow into the second semiconductor region FD2 in accordance with the input signal.
- a low level signal for example, ground potential
- a potential barrier is generated by the second gate electrode TX2. Accordingly, the charge generated in the semiconductor substrate 1A is not drawn into the second semiconductor region FD2.
- the potential in the region immediately below the third gate electrode TX3 is compared to the potential in the region immediately below the photogate electrodes PG1 and PG2 in the semiconductor substrate 1A. Become lower. Thereby, negative charges (electrons) are drawn in the direction of the third gate electrode TX3 and accumulated in the potential well formed by the third semiconductor region FD3.
- a low level signal for example, ground potential
- a potential barrier is generated by the third gate electrode TX3. Accordingly, the charge generated in the semiconductor substrate 1A is not drawn into the third semiconductor region FD3.
- the third semiconductor region FD3 collects some of the charges generated in the charge generation region in response to the incidence of light as unnecessary charges.
- Pulse light L D from the object incident from the light incident surface 1FT of the semiconductor substrate 1A leads to the light receiving region provided on the surface side of the semiconductor substrate 1A (charge-generation region).
- the charge generated in the semiconductor substrate 1A with the incidence of the pulsed light is generated from each charge generation region (each region immediately below the photogate electrodes PG1 and PG2) from the first or second gate adjacent to the corresponding charge generation region. It is sent to a region immediately below the electrodes TX1 and TX2.
- the gate signal S 1, S 2 for detecting that synchronism with the pulse drive signal S P output light source to the first and second gate electrodes TX1, TX2, via the wiring board 10, given alternating, each charge generation region
- the charges generated in the above flow into the regions immediately below the first or second gate electrodes TX1 and TX2, respectively, and flow into the first or second semiconductor regions FD1 and FD2.
- the ratio of the charge amounts Q1 and Q2 accumulated in the first semiconductor region FD1 or the second semiconductor region FD2 to the total charge amount (Q1 + Q2) is equal to the outgoing pulse light emitted by applying the pulse drive signal SP to the light source. This corresponds to the phase difference of the detection pulse light returned by reflecting the outgoing pulse light by the object H.
- the distance image sensor 1 includes a back gate semiconductor region for fixing the potential of the semiconductor substrate 1A to a reference potential.
- FIG. 6 and 7 are diagrams showing a potential distribution in the vicinity of the light incident surface 1FT of the semiconductor substrate 1A for explaining the charge accumulation operation.
- FIG. 8 is a diagram illustrating a potential distribution in the vicinity of the light incident surface 1FT of the semiconductor substrate 1A for explaining the charge discharging operation. 6 to 8, the downward direction is the positive direction of the potential. 6 to 8 show potential distributions along the line VV in FIG.
- a photogate electrode is generated by a potential applied to the photogate electrodes PG1 and PG2 (for example, an intermediate potential between a higher potential and a lower potential applied to the first and second gate electrodes TX1 and TX2).
- the potentials ⁇ PG1 and ⁇ PG2 in the region immediately below PG1 and PG2 are set slightly higher than the substrate potential.
- the potential ⁇ FD1 of the region FD1, the potential ⁇ FD2 of the second semiconductor region FD2 , and the potential ⁇ FD3 of the third semiconductor region FD3 are shown.
- High potential of the detection gate signals S 1 is inputted to the first gate electrode TX1, as shown in FIG. 6, mainly charges generated immediately under the photo gate electrode PG1, according to potential gradient, the first Accumulation is performed in the potential well of the first semiconductor region FD1 via the region immediately below the gate electrode TX1. A charge amount Q1 is accumulated in the potential well of the first semiconductor region FD1. A low level potential (for example, a ground potential) is applied to the second gate electrode TX2. For this reason, the potential ⁇ TX2 in the region immediately below the second gate electrode TX2 does not decrease, and no charge flows into the potential well of the second semiconductor region FD2.
- a low level potential for example, a ground potential
- the high potential of the detection gate signal S 2 is inputted to the second gate electrode TX2, as shown in FIG. 7, occurred primarily just below the photo gate electrode PG2
- the electric charge is accumulated in the potential well of the second semiconductor region FD2 through the region immediately below the second gate electrode TX2 according to the potential gradient.
- a charge amount Q2 is accumulated in the potential well of the second semiconductor region FD2.
- a low level potential (for example, a ground potential) is applied to the first gate electrode TX1. For this reason, the potential ⁇ TX1 in the region immediately below the first gate electrode TX1 does not decrease, and no charge flows into the potential well of the first semiconductor region FD1.
- the third gate electrode TX3, low (For example, ground potential). For this reason, the potential ⁇ TX3 in the region immediately below the third gate electrode TX3 does not drop, and no charge flows into the potential well of the third semiconductor region FD3.
- FIG. 9 is a schematic diagram for explaining the configuration of a pixel.
- the second gate electrode TX2, the detection gate signal S 2 is supplied as a charge transfer signal. That is, charge transfer signals having different phases are applied to the first gate electrode TX1 and the second gate electrode TX2.
- the third gate electrode TX3, is given a charge transfer signal S 3.
- Charges generated in (the region immediately below the mainly photogate electrode PG1) charge generation region when the detection gate signals S 1 of high level is applied to the first gate electrode TX1 is the first semiconductor region FD1 It flows as a signal charge into the configured potential well.
- the signal charges accumulated in the first semiconductor region FD1 is read out from the first semiconductor region FD1 as an output corresponding to the accumulated charge amount Q 1 (V out1).
- Charges generated in (the region immediately below the mainly photogate electrode PG2) charge generation region when the detection gate signal S 2 of high level is applied to the second gate electrode TX2 is by the second semiconductor region FD2 It flows as a signal charge into the configured potential well.
- the signal charges accumulated in the second semiconductor region FD2 is read out from the second semiconductor region FD2 as an output corresponding to the accumulated charge amount Q 2 (V out2).
- These outputs (V out1 , V out2 ) correspond to the signal d ′ (m, n) described above.
- FIG. 10 is a timing chart of various actual signals.
- the period of one frame includes a period for accumulating signal charges (accumulation period) and a period for reading signal charges (readout period). Focusing on a single pixel, the accumulation period, the signal based on the pulse drive signal S P is applied to the light source, in synchronization with this, the detection gate signals S 1 applied to the first gate electrode TX1. Then, the detection gate signal S 2, a predetermined phase difference detection gate signal S 1 (e.g., a phase difference of 180 degrees) is applied to the second gate electrode TX2 in. Prior to the distance measurement, a reset signal is applied to the first and second semiconductor regions FD1 and FD2, and the charges accumulated inside are discharged to the outside.
- accumulation period Focusing on a single pixel, the accumulation period, the signal based on the pulse drive signal S P is applied to the light source, in synchronization with this, the detection gate signals S 1 applied to the first gate electrode TX1. Then, the detection gate signal S 2, a predetermined phase difference detection gate signal S 1 (e.g.,
- the pulses of the detection gate signals S 1 and S 2 are sequentially applied to the first and second gate electrodes TX1 and TX2, and further, charge transfer is performed in synchronization therewith. It is done sequentially. Then, signal charges are accumulated and accumulated in the first and second semiconductor regions FD1, FD2.
- the signal charges accumulated in the first and second semiconductor regions FD1, FD2 are read out.
- the charge transfer signal S 3 applied to the third gate electrode TX3 becomes high level, the positive potential is applied to the third gate electrode TX3, unnecessary charges are collected in the potential well of the third semiconductor region FD3 .
- the charge transfer signal S 3 applied to the third gate electrode TX3 is a high level.
- Potential V PG applied to the photo gate electrode PG1, PG2 is set lower than the potential V TX1, V TX2, V TX31 , V TX32.
- the detection gate signals S 1 and S 2 become high level, the potentials ⁇ TX1 and ⁇ TX2 become lower than the potentials ⁇ PG1 and ⁇ PG2 .
- the potential phi TX3 is potential phi PG1, lower than phi PG2.
- the potential V PG is set higher than the potential when the detection gate signals S 1 and S 2 and the charge transfer signal S 3 are at a low level.
- the detection gate signals S 1 and S 2 become low level, the potentials ⁇ TX1 and ⁇ TX2 become higher than the potentials ⁇ PG1 and ⁇ PG2 .
- the potential phi TX3 is potential phi PG1, higher than phi PG2.
- the outer edge of the charge generation region (the region immediately below the photogate electrodes PG1 and PG2) extends to each side of the pixel regions PA1 and PA2 excluding the corners of the pixel regions PA1 and PA2. Therefore, the area of the charge generation region is expanded. Thereby, an aperture ratio can be improved.
- the charges generated in the regions corresponding to the corners of the pixel regions PA1 and PA2 in the charge generation region are in the center of the pixel regions PA1 and PA2.
- the moving distance to the arranged first and second semiconductor regions FD1, FD2 is long. For this reason, the transfer time of the charge generated in the region corresponding to the corner to the first and second semiconductor regions FD1, FD2 becomes long, and the transfer efficiency of the signal charge to the first and second semiconductor regions FD1, FD2 is increased. Gets worse.
- the charge generation regions are not arranged at the corners of the pixel regions PA1 and PA2, the signal charge is transferred from the region where the movement distance becomes long. There is no. For this reason, the transfer efficiency of the signal charge to the first and second semiconductor regions FD1, FD2 is improved.
- the third semiconductor region FD3 is disposed at the corners of the pixel regions PA1 and PA2 where the charge generation region is not disposed. Therefore, the third semiconductor region FD3 can be disposed without hindering improvement in the aperture ratio and charge transfer efficiency.
- the distance detection accuracy can be improved.
- the first and second semiconductor regions FD1, FD2 are located inside the photogate electrodes PG1, PG2, and the area of the first and second semiconductor regions FD1, FD2 is the photogate electrode PG1.
- PG2 is set smaller than the area.
- the first and second semiconductor regions FD1, FD1, FD2, FD1, FD2 in the region immediately below the photogate electrodes PG1, PG2 charge generation region
- the area of FD2 is relatively greatly reduced.
- the charges (charge amounts Q1, Q2) transferred to and accumulated in the first and second semiconductor regions FD1, FD2 are expressed by the following relational expression according to the capacitances (Cfd) of the first and second semiconductor regions FD1, FD2.
- the first gate electrode TX1 surrounds the entire circumference of the first semiconductor region FD1.
- the second gate electrode TX2 surrounds the entire circumference of the second semiconductor region FD2. For this reason, signal charges are collected in the first and second semiconductor regions FD1, FD2 from all directions of the first and second semiconductor regions FD1, FD2. As a result, the area efficiency (aperture ratio) of the imaging region can be increased.
- the charge generation regions of the plurality of pixel regions PA1 and PA2 are integrally formed, and the photogate electrodes PG1 and PG2 of the plurality of pixel regions PA1 and PA2 are integrally formed.
- the utilization efficiency of a sensor area can be improved.
- the third semiconductor regions FD3 of the plurality of pixel regions PA1, PA2 are integrally formed. Also by this, the utilization efficiency of a sensor area can be improved.
- FIG. 11 differs from the above-described embodiment in that the first unit arranged in one pixel area PA1 constitutes one pixel P (m, n).
- FIG. 11 is a schematic diagram for explaining a configuration of a pixel of a distance image sensor according to a modification.
- the distance image sensor includes a photogate electrode PG1, a first gate electrode TX1, a plurality of third gate electrodes TX3, a first semiconductor region FD1, and a third gate in each pixel P (m, n). And a semiconductor region FD3.
- the configuration of one pixel area PA1 constituting each pixel P (m, n) is the same as the configuration of the pixel area PA1 in the above-described embodiment.
- the photogate electrode PG1 of each pixel area PA1 is continuous in the row direction and the column direction by extending the outer edge to each side of the pixel area PA1.
- the third semiconductor region FD3 of each pixel region PA1 is formed integrally with the third semiconductor regions FD3 adjacent in the row direction and the column direction.
- the four third semiconductor regions FD3 located at the center of these pixel regions PA1 have a rectangular shape (specifically, a square shape).
- the third gate electrode TX3 of each pixel area PA1 is continuous in the row direction and the column direction by extending the respective end portions to the sides of the pixel area PA1.
- the four third gate electrodes TX3 located at the center of these pixel areas PA1 have a substantially rectangular ring shape.
- FIG. 12 is a timing chart of various signals in the modification shown in FIG.
- the detection gate signals S 1 applied to the first gate electrode TX1 is given intermittently phase shifted by a predetermined Taiminku.
- the detection gate signals S 1 is given 180 degree phase shift at the timing of 180 degrees.
- Detection gate signals S 1 is synchronized with the pulse drive signal S P 0 degree timing, it has a phase difference of 180 degrees to the pulse drive signal S P at a timing of 180 degrees.
- a detection gate signals S 1 and the charge transfer signal S 3 are opposite in phase.
- the signal charge accumulated in the first semiconductor region FD1 at the timing of 0 degrees is read from the first semiconductor region FD1 as an output (V out1 ), and is read into the first semiconductor region FD1 at the timing of 180 degrees.
- the accumulated signal charge is read out from the first semiconductor region FD1 as an output (V out2 ).
- These outputs (V out1 , V out2 ) correspond to the signal d ′ (m, n) described above.
- One pixel area PA1 including the photogate electrode PG1 corresponds to one pixel, and the distance is calculated based on the output from the same pixel. For this reason, variation in distance calculation can be reduced as compared with the configuration in which the plurality of pixel areas PA1 and PA2 correspond to one pixel. Further, the utilization efficiency of the sensor area can be increased, and the spatial resolution can be improved.
- Detection gate signals S 1 is supplied with 90 degree phase shift at the timing of 90 degrees, given 180 degree phase shift at the timing of 180 degrees, it is given a 270 degree phase shift at the timing of 270 degrees May be.
- signal charges accumulated in the first semiconductor region FD1 at timings of 0 degrees, 90 degrees, 180 degrees, and 270 degrees are read out from the first semiconductor region FD1 as outputs, and distances are based on these outputs. Is calculated.
- FIG. 13 is different from the above-described embodiment in that an area RE in which the readout circuit RC is arranged is set in the modification example shown in FIG.
- FIG. 13 is a schematic diagram for explaining a configuration of a pixel of a distance image sensor according to a modification.
- a region RE in which the readout circuit RC is arranged is set for each of the pixel regions PA1 and PA2.
- the readout circuit RC reads out a signal corresponding to the charge amount accumulated in the first or second semiconductor region FD1, FD2 of the corresponding pixel region PA1, PA2.
- the readout circuit RC is composed of a floating diffusion amplifier (FDA: Floating Diffusion Amplifier) and the like.
- FDA Floating Diffusion Amplifier
- the region RE is located outside the corresponding pixel regions PA1 and PA2 along one side of the pixel regions PA1 and PA2. In this modification, the region RE is located along one side extending in the row direction of each pixel region PA1, PA2, and is located between the pixel regions PA1, PA2 adjacent in the column direction.
- a third gate electrode TX3 1 provided in the pixel area PA1 a third gate electrode TX3 2 provided in the pixel area PA2, but are spatially separated.
- the third gate electrode TX3 1, the charge transfer signal S 31 is supplied to the third gate electrode TX3 2, the charge transfer signal S 32 is applied.
- FIG. 14 is a timing chart of various signals in the modification shown in FIG.
- the detection gate signal S 1 is applied to the first gate electrode TX1
- the third gate electrode TX3 1 low-level potential (e.g., ground potential) is applied. Therefore, the potential phi TX31 the region immediately below the third gate electrode TX3 1 is not lowered, the third semiconductor potential well region FD3, charge does not flow into.
- the detection gate signal S 2 is applied to the second gate electrode TX2, the third gate electrode TX3 2, low-level potential (e.g., ground potential) is applied. Therefore, the potential phi TX32 the region immediately below the third gate electrode TX3 2 is not lowered, the third semiconductor potential well region FD3, charge does not flow into.
- the charge transfer signals S 31 and S 32 applied to the third gate electrodes TX3 1 and TX3 2 become high level, a positive potential is applied to the third gate electrodes TX3 1 and TX3 2 , and unnecessary charges are supplied to the third semiconductor region. Collected in the potential well of FD3.
- a detection gate signals S 1 and the charge transfer signal S 31 is the inverse of the phase.
- a detection gate signal S 2 and the charge transfer signal S 32 is the inverse of the phase.
- the read circuit RC can be arranged without hindering improvement in the aperture ratio and the charge transfer efficiency.
- the region RE may be located along one side extending in the column direction of each pixel region PA1, PA2. In this case, the region RE is located between the pixel regions PA1 and PA2 adjacent in the row direction.
- FIG. 15 is different from the modification example shown in FIG. 11 in that the region RE in which the readout circuit RC is arranged is set in the modification example shown in FIG.
- FIG. 15 is a schematic diagram for explaining a configuration of a pixel of a distance image sensor according to a modification.
- the region RE is located along one side extending in the row direction of each pixel region PA1, PA2, and is adjacent to the pixel region PA1, adjacent in the column direction. Located between PA2.
- the region RE may be located along one side extending in the column direction of each pixel region PA1, PA2.
- FIG. 16 is different from the modification shown in FIG. 13 in the position of the region RE.
- FIG. 16 is a schematic diagram for explaining a configuration of pixels of a distance image sensor according to a modification.
- a region RE in which the readout circuit RC is disposed is located at one corner of each pixel region PA1, PA2. That is, the third gate electrodes TX3 1 , TX3 2 and the third semiconductor region FD3 are not arranged at the corner where the region RE is located.
- the region RE is set in each pixel region PA1, PA2.
- the read circuit RC can be arranged without hindering improvement in the aperture ratio and the charge transfer efficiency.
- the region RE may be located at other corners of the pixel regions PA1 and PA2.
- FIG. 17 is a schematic diagram for explaining a configuration of a pixel of a distance image sensor according to a modification.
- a region RE in which the readout circuit RC is disposed is located at one corner of each pixel region PA1, PA2. That is, the third gate electrodes TX3 1 , TX3 2 and the third semiconductor region FD3 are not arranged at the corner where the region RE is located.
- the region RE is set in each pixel region PA1, PA2.
- the read circuit RC can be arranged without hindering improvement in the aperture ratio and the charge transfer efficiency.
- the region RE may be located at other corners of the pixel regions PA1 and PA2.
- the shape of the pixel areas PA1 and PA2 is not limited to a rectangular shape (square shape).
- the pixel areas PA1 and PA2 may have, for example, a triangular shape or five or more polygonal shapes.
- the distance image sensor 1 is not limited to the surface incident type distance image sensor.
- the distance image sensor 1 may be a back-illuminated distance image sensor.
- the charge generation region in which charge is generated in response to incident light may be configured by a photodiode (for example, an embedded photodiode).
- the distance image sensor 1 is not limited to the one in which the pixels P (m, n) are two-dimensionally arranged, and may be one in which the pixels P (m, n) are one-dimensionally arranged.
- the p-type and n-type conductivity types in the distance image sensor 1 according to the present embodiment may be switched so as to be opposite to those described above.
- the present invention can be used for a product monitor in a factory production line, or a distance sensor and a distance image sensor mounted on a vehicle or the like.
- SYMBOLS 1 Distance image sensor, 1A ... Semiconductor substrate, 1B ... Imaging region, FD1 ... First semiconductor region, FD2 ... Second semiconductor region, FD3 ... Third semiconductor region, P ... Pixel, PA1, PA2 ... Pixel region, PG1, PG2 ... photo gate electrode, RC ... read circuit, region RE ... read circuit is arranged, TX1 ... first gate electrode, TX2 ... second gate electrode, TX3, TX3 1, TX3 2 ... third gate electrode.
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Electromagnetism (AREA)
- General Physics & Mathematics (AREA)
- Remote Sensing (AREA)
- Radar, Positioning & Navigation (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Computer Networks & Wireless Communication (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Solid State Image Pick-Up Elements (AREA)
- Optical Radar Systems And Details Thereof (AREA)
- Transforming Light Signals Into Electric Signals (AREA)
- Measurement Of Optical Distance (AREA)
Abstract
Description
パルス駆動信号SP:
V(t)=1(但し、0<t<(T/2)の場合)
V(t)=0(但し、(T/2)<t<Tの場合)
V(t+T)=V(t)
検出用ゲート信号S1:
V(t)=1(但し、0<t<(T/2)の場合)
V(t)=0(但し、(T/2)<t<Tの場合)
V(t+T)=V(t)
検出用ゲート信号S2(=S1の反転):
V(t)=0(但し、0<t<(T/2)の場合)
V(t)=1(但し、(T/2)<t<Tの場合)
V(t+T)=V(t)
半導体基板1Aの第一基板領域1Aa:厚さ5~700μm/不純物濃度1×1018~1020cm-3
半導体基板1Aの第二基板領域1Ab:厚さ3~50μm/不純物濃度1×1013~1016cm-3
第一及び第二半導体領域FD1,FD2:厚さ0.1~0.4μm/不純物濃度1×1018~1020cm-3
第三半導体領域FD3:厚さ0.1~0.4μm/不純物濃度1×1018~1020cm-3
ΔV=Q1/Cfd
ΔV=Q2/Cfd
したがって、第一及び第二半導体領域FD1,FD2の面積が低減されると、第一及び第二半導体領域FD1,FD2の静電容量(Cfd)も低減され、発生する電圧変化(ΔV)が大きくなる。すなわち、電荷電圧変換ゲインが高くなる。この結果、距離画像センサ1の高感度化を図ることができる。
Claims (9)
- 距離センサであって、
多角形状の画素領域の角部を除く前記画素領域の各辺まで外縁が延びており、入射光に応じて電荷が発生する電荷発生領域と、
前記画素領域の中心部で且つ前記電荷発生領域に囲まれるように前記電荷発生領域の内側に配置され、前記電荷発生領域からの信号電荷を収集する信号電荷収集領域と、
前記画素領域の角部で且つ前記電荷発生領域の外側に配置され、前記電荷発生領域からの不要電荷を収集する不要電荷収集領域と、
前記電荷発生領域の上に配置されるフォトゲート電極と、
前記信号電荷収集領域と前記電荷発生領域との間に配置され、入力された信号に応じて前記電荷発生領域からの信号電荷を前記信号電荷収集領域に流入させる転送電極と、
前記不要電荷収集領域と前記電荷発生領域との間に配置され、入力された信号に応じて前記電荷発生領域からの不要電荷を前記不要電荷収集領域に流入させる不要電荷収集ゲート電極と、を備えている。 - 請求項1に記載の距離センサであって、
隣り合う複数の前記画素領域を備えており、
前記複数の画素領域の前記電荷発生領域同士が、一体的に形成され、
前記複数の画素領域の前記フォトゲート電極同士が、一体的に形成されている。 - 請求項2に記載の距離センサであって、
前記複数の画素領域の前記不要電荷収集領域同士が、一体的に形成されている。 - 請求項2又は3に記載の距離センサであって、
前記複数の画素領域の前記転送電極には、異なる位相の電荷転送信号がそれぞれ与えられる。 - 請求項1~3のいずれか一項に記載の距離センサであって、
前記転送電極には、所定のタイミンクで間欠的に位相シフトが与えられた電荷転送信号が与えられる。 - 請求項1~5のいずれか一項に記載の距離センサであって、
前記信号電荷収集領域に蓄積された電荷量に対応する信号を読み出す読出回路が配置される領域が、前記画素領域の一辺に沿って前記画素領域の外側に位置している。 - 請求項1~5のいずれか一項に記載の距離センサであって、
前記信号電荷収集領域に蓄積された電荷量に対応する信号を読み出す読出回路が配置される領域が、前記画素領域の一つの角部に位置している。 - 請求項1~7のいずれか一項に記載の距離センサであって、
前記信号電荷収集領域は、平面視で矩形状であり、
前記転送電極は、略多角形環状を呈している。 - 一次元状又は二次元状に配置された複数のユニットからなる撮像領域を半導体基板上に備え、前記ユニットから出力される電荷量に基づいて、距離画像を得る距離画像センサであって、
前記ユニットそれぞれが、請求項1~8のいずれか一項に記載の距離センサである。
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CH01304/14A CH708005B1 (de) | 2012-03-02 | 2012-11-13 | Bereichssensor und Bereichsbildsensor. |
DE201211005967 DE112012005967T5 (de) | 2012-03-02 | 2012-11-13 | Bereichssensor und Bereichsbildsensor |
KR1020147021762A KR102028223B1 (ko) | 2012-03-02 | 2012-11-13 | 거리 센서 및 거리 화상 센서 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2012046844A JP5932400B2 (ja) | 2012-03-02 | 2012-03-02 | 距離センサ及び距離画像センサ |
JP2012-046844 | 2012-03-02 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2013128723A1 true WO2013128723A1 (ja) | 2013-09-06 |
Family
ID=49042331
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2012/079415 WO2013128723A1 (ja) | 2012-03-02 | 2012-11-13 | 距離センサ及び距離画像センサ |
Country Status (6)
Country | Link |
---|---|
US (1) | US9053998B2 (ja) |
JP (1) | JP5932400B2 (ja) |
KR (1) | KR102028223B1 (ja) |
CH (1) | CH708005B1 (ja) |
DE (1) | DE112012005967T5 (ja) |
WO (1) | WO2013128723A1 (ja) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10116925B1 (en) * | 2017-05-16 | 2018-10-30 | Samsung Electronics Co., Ltd. | Time-resolving sensor using shared PPD + SPAD pixel and spatial-temporal correlation for range measurement |
WO2020202779A1 (ja) * | 2019-03-29 | 2020-10-08 | 株式会社ブルックマンテクノロジ | 固体撮像装置、撮像システム及び撮像方法 |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009276243A (ja) * | 2008-05-15 | 2009-11-26 | Hamamatsu Photonics Kk | 距離センサ及び距離画像センサ |
JP2011112382A (ja) * | 2009-11-24 | 2011-06-09 | Hamamatsu Photonics Kk | 距離センサ及び距離画像センサ |
JP2011112614A (ja) * | 2009-11-30 | 2011-06-09 | Hamamatsu Photonics Kk | 距離センサ及び距離画像センサ |
JP2011133464A (ja) * | 2009-11-24 | 2011-07-07 | Hamamatsu Photonics Kk | 距離センサ及び距離画像センサ |
JP2011179926A (ja) * | 2010-02-26 | 2011-09-15 | Hamamatsu Photonics Kk | 距離画像センサ |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3832441B2 (ja) * | 2002-04-08 | 2006-10-11 | 松下電工株式会社 | 強度変調光を用いた空間情報の検出装置 |
EP2304795A1 (en) | 2008-07-17 | 2011-04-06 | Microsoft International Holdings B.V. | Cmos photogate 3d camera system having improved charge sensing cell and pixel geometry |
DE102011079589A1 (de) * | 2010-08-11 | 2012-02-16 | Samsung Electronics Co., Ltd. | Einheitspixel für ein Photodetektionsbauelement |
US9134401B2 (en) | 2012-03-27 | 2015-09-15 | Hamamatsu Photonics K. K. | Range sensor and range image sensor |
-
2012
- 2012-03-02 JP JP2012046844A patent/JP5932400B2/ja active Active
- 2012-03-09 US US13/415,966 patent/US9053998B2/en active Active
- 2012-11-13 CH CH01304/14A patent/CH708005B1/de unknown
- 2012-11-13 KR KR1020147021762A patent/KR102028223B1/ko active IP Right Grant
- 2012-11-13 DE DE201211005967 patent/DE112012005967T5/de active Pending
- 2012-11-13 WO PCT/JP2012/079415 patent/WO2013128723A1/ja active Application Filing
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009276243A (ja) * | 2008-05-15 | 2009-11-26 | Hamamatsu Photonics Kk | 距離センサ及び距離画像センサ |
JP2011112382A (ja) * | 2009-11-24 | 2011-06-09 | Hamamatsu Photonics Kk | 距離センサ及び距離画像センサ |
JP2011133464A (ja) * | 2009-11-24 | 2011-07-07 | Hamamatsu Photonics Kk | 距離センサ及び距離画像センサ |
JP2011112614A (ja) * | 2009-11-30 | 2011-06-09 | Hamamatsu Photonics Kk | 距離センサ及び距離画像センサ |
JP2011179926A (ja) * | 2010-02-26 | 2011-09-15 | Hamamatsu Photonics Kk | 距離画像センサ |
Also Published As
Publication number | Publication date |
---|---|
JP2013181890A (ja) | 2013-09-12 |
JP5932400B2 (ja) | 2016-06-08 |
DE112012005967T5 (de) | 2014-11-13 |
US20130228828A1 (en) | 2013-09-05 |
KR102028223B1 (ko) | 2019-10-02 |
CH708005B1 (de) | 2016-02-15 |
KR20140138618A (ko) | 2014-12-04 |
US9053998B2 (en) | 2015-06-09 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP6006514B2 (ja) | 距離センサ及び距離画像センサ | |
JP5518667B2 (ja) | 距離センサ及び距離画像センサ | |
JP6026755B2 (ja) | 距離センサ及び距離画像センサ | |
WO2015190308A1 (ja) | 測距装置 | |
JPWO2018042785A1 (ja) | 距離センサ及び距離画像センサ | |
US9494688B2 (en) | Range sensor and range image sensor | |
JP6010425B2 (ja) | 距離センサ及び距離画像センサ | |
JP2012083213A (ja) | 距離センサ及び距離画像センサ | |
JP5932400B2 (ja) | 距離センサ及び距離画像センサ | |
JP2012083214A (ja) | 距離センサ及び距離画像センサ | |
JP2012083221A (ja) | 距離センサ及び距離画像センサ | |
JP2012083220A (ja) | 距離センサ及び距離画像センサ | |
JP2012083219A (ja) | 距離センサ及び距離画像センサ | |
JP2012083222A (ja) | 距離センサ及び距離画像センサ |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 12869593 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 20147021762 Country of ref document: KR Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 10201400001304 Country of ref document: CH |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1120120059670 Country of ref document: DE Ref document number: 112012005967 Country of ref document: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 12869593 Country of ref document: EP Kind code of ref document: A1 |